source: src/Parser/lex.ll@ f8de4e4

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr persistent-indexer pthread-emulation qualifiedEnum
Last change on this file since f8de4e4 was e15853c, checked in by Peter A. Buhr <pabuhr@…>, 7 years ago

remove leading underscores in enums for _FloatNN and _Bool

  • Property mode set to 100644
File size: 18.9 KB
Line 
1/*
2 * Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3 *
4 * The contents of this file are covered under the licence agreement in the
5 * file "LICENCE" distributed with Cforall.
6 *
7 * lex.ll --
8 *
9 * Author : Peter A. Buhr
10 * Created On : Sat Sep 22 08:58:10 2001
11 * Last Modified By : Peter A. Buhr
12 * Last Modified On : Wed Feb 13 17:33:53 2019
13 * Update Count : 702
14 */
15
16%option yylineno
17%option noyywrap
18%option nounput
19
20%{
21// The lexer assumes the program has been preprocessed by cpp. Hence, all user level preprocessor directive have been
22// performed and removed from the source. The only exceptions are preprocessor directives passed to the compiler (e.g.,
23// line-number directives) and C/C++ style comments, which are ignored.
24
25//**************************** Includes and Defines ****************************
26
27// trigger before each matching rule's action
28#define YY_USER_ACTION \
29 yylloc.first_line = yylineno; \
30 yylloc.first_column = column; \
31 column += yyleng; \
32 yylloc.last_column = column; \
33 yylloc.last_line = yylineno; \
34 yylloc.filename = yyfilename ? yyfilename : "";
35unsigned int column = 0; // position of the end of the last token parsed
36
37#include <string>
38#include <cstdio> // FILENAME_MAX
39using namespace std;
40
41#include "config.h" // configure info
42#include "ParseNode.h"
43#include "TypedefTable.h"
44
45char *yyfilename;
46string *strtext; // accumulate parts of character and string constant value
47
48#define RETURN_LOCN(x) yylval.tok.loc.file = yyfilename; yylval.tok.loc.line = yylineno; return( x )
49#define RETURN_VAL(x) yylval.tok.str = new string( yytext ); RETURN_LOCN( x )
50#define RETURN_CHAR(x) yylval.tok.str = nullptr; RETURN_LOCN( x )
51#define RETURN_STR(x) yylval.tok.str = strtext; RETURN_LOCN( x )
52
53#define WHITE_RETURN(x) // do nothing
54#define NEWLINE_RETURN() column = 0; WHITE_RETURN( '\n' )
55#define ASCIIOP_RETURN() RETURN_CHAR( (int)yytext[0] ) // single character operator
56#define NAMEDOP_RETURN(x) RETURN_CHAR( x ) // multichar operator, with a name
57#define NUMERIC_RETURN(x) rm_underscore(); RETURN_VAL( x ) // numeric constant
58#define KEYWORD_RETURN(x) RETURN_CHAR( x ) // keyword
59#define QKEYWORD_RETURN(x) RETURN_VAL(x); // quasi-keyword
60#define IDENTIFIER_RETURN() RETURN_VAL( typedefTable.isKind( yytext ) )
61#define ATTRIBUTE_RETURN() RETURN_VAL( ATTR_IDENTIFIER )
62
63#ifdef HAVE_KEYWORDS_FLOATXX // GCC >= 7 => keyword, otherwise typedef
64#define FLOATXX(v) KEYWORD_RETURN(v);
65#else
66#define FLOATXX(v) IDENTIFIER_RETURN();
67#endif // HAVE_KEYWORDS_FLOATXX
68
69void rm_underscore() {
70 // SKULLDUGGERY: remove underscores (ok to shorten?)
71 yyleng = 0;
72 for ( int i = 0; yytext[i] != '\0'; i += 1 ) { // copying non-underscore characters to front of string
73 if ( yytext[i] != '_' ) {
74 yytext[yyleng] = yytext[i];
75 yyleng += 1;
76 } // if
77 } // for
78 yytext[yyleng] = '\0';
79} // rm_underscore
80
81// Stop warning due to incorrectly generated flex code.
82#pragma GCC diagnostic ignored "-Wsign-compare"
83%}
84
85binary [0-1]
86octal [0-7]
87nonzero [1-9]
88decimal [0-9]
89hex [0-9a-fA-F]
90universal_char "\\"((u"_"?{hex_quad})|(U"_"?{hex_quad}{2}))
91
92 // identifier, GCC: $ in identifier
93identifier ([a-zA-Z_$]|{universal_char})([0-9a-zA-Z_$]|{universal_char})*
94
95 // attribute identifier, GCC: $ in identifier
96attr_identifier "@"{identifier}
97
98 // numeric constants, CFA: '_' in constant
99hex_quad {hex}("_"?{hex}){3}
100size_opt (8|16|32|64|128)?
101length ("ll"|"LL"|[lL]{size_opt})|("hh"|"HH"|[hH])
102integer_suffix_opt ("_"?(([uU]({length}?[iI]?)|([iI]{length}))|([iI]({length}?[uU]?)|([uU]{length}))|({length}([iI]?[uU]?)|([uU][iI]))|[zZ]))?
103
104octal_digits ({octal})|({octal}({octal}|"_")*{octal})
105octal_prefix "0""_"?
106octal_constant (("0")|({octal_prefix}{octal_digits})){integer_suffix_opt}
107
108nonzero_digits ({nonzero})|({nonzero}({decimal}|"_")*{decimal})
109decimal_constant {nonzero_digits}{integer_suffix_opt}
110
111binary_digits ({binary})|({binary}({binary}|"_")*{binary})
112binary_prefix "0"[bB]"_"?
113binary_constant {binary_prefix}{binary_digits}{integer_suffix_opt}
114
115hex_digits ({hex})|({hex}({hex}|"_")*{hex})
116hex_prefix "0"[xX]"_"?
117hex_constant {hex_prefix}{hex_digits}{integer_suffix_opt}
118
119 // GCC: D (double) and iI (imaginary) suffixes, and DL (long double)
120exponent "_"?[eE]"_"?[+-]?{decimal_digits}
121floating_size 16|32|32x|64|64x|80|128|128x
122floating_length ([fFdDlLwWqQ]|[fF]{floating_size})
123floating_suffix ({floating_length}?[iI]?)|([iI]{floating_length})
124floating_suffix_opt ("_"?({floating_suffix}|"DL"))?
125decimal_digits ({decimal})|({decimal}({decimal}|"_")*{decimal})
126floating_decimal {decimal_digits}"."{exponent}?{floating_suffix_opt}
127floating_fraction "."{decimal_digits}{exponent}?{floating_suffix_opt}
128floating_constant ({decimal_digits}{exponent}{floating_suffix_opt})|({decimal_digits}{floating_fraction})
129
130binary_exponent "_"?[pP]"_"?[+-]?{decimal_digits}
131hex_floating_suffix_opt ("_"?({floating_suffix}))?
132hex_floating_fraction ({hex_digits}?"."{hex_digits})|({hex_digits}".")
133hex_floating_constant {hex_prefix}(({hex_floating_fraction}{binary_exponent})|({hex_digits}{binary_exponent})){hex_floating_suffix_opt}
134
135 // character escape sequence, GCC: \e => esc character
136simple_escape "\\"[abefnrtv'"?\\]
137 // ' stop editor highlighting
138octal_escape "\\"{octal}("_"?{octal}){0,2}
139hex_escape "\\""x""_"?{hex_digits}
140escape_seq {simple_escape}|{octal_escape}|{hex_escape}|{universal_char}
141cwide_prefix "L"|"U"|"u"
142swide_prefix {cwide_prefix}|"u8"
143
144 // display/white-space characters
145h_tab [\011]
146form_feed [\014]
147v_tab [\013]
148c_return [\015]
149h_white [ ]|{h_tab}
150
151 // overloadable operators
152op_unary_only "~"|"!"
153op_unary_binary "+"|"-"|"*"
154op_unary_pre_post "++"|"--"
155op_unary {op_unary_only}|{op_unary_binary}|{op_unary_pre_post}
156
157op_binary_only "/"|"%"|"\\"|"^"|"&"|"|"|"<"|">"|"="|"=="|"!="|"<<"|">>"|"<="|">="|"+="|"-="|"*="|"/="|"%="|"\\="|"&="|"|="|"^="|"<<="|">>="
158op_binary_over {op_unary_binary}|{op_binary_only}
159 // op_binary_not_over "?"|"->"|"."|"&&"|"||"|"@="
160 // operator {op_unary_pre_post}|{op_binary_over}|{op_binary_not_over}
161
162%x COMMENT
163%x BKQUOTE
164%x QUOTE
165%x STRING
166
167%%
168 /* line directives */
169^{h_white}*"#"{h_white}*[0-9]+{h_white}*["][^"\n]+["].*"\n" {
170 /* " stop editor highlighting */
171 static char filename[FILENAME_MAX]; // temporarily store current source-file name
172 char *end_num;
173 char *begin_string, *end_string;
174 long lineno, length;
175 lineno = strtol( yytext + 1, &end_num, 0 );
176 begin_string = strchr( end_num, '"' );
177 if ( begin_string ) { // file name ?
178 end_string = strchr( begin_string + 1, '"' ); // look for ending delimiter
179 assert( end_string ); // closing quote ?
180 length = end_string - begin_string - 1; // file-name length without quotes or sentinel
181 assert( length < FILENAME_MAX ); // room for sentinel ?
182 memcpy( &filename, begin_string + 1, length ); // copy file name from yytext
183 filename[ length ] = '\0'; // terminate string with sentinel
184 //cout << "file " << filename << " line " << lineno << endl;
185 yylineno = lineno;
186 yyfilename = filename;
187 } // if
188}
189
190 /* preprocessor-style directives */
191^{h_white}*"#"[^\n]*"\n" { RETURN_VAL( DIRECTIVE ); }
192
193 /* ignore C style comments (ALSO HANDLED BY CPP) */
194"/*" { BEGIN COMMENT; }
195<COMMENT>.|\n ;
196<COMMENT>"*/" { BEGIN 0; }
197
198 /* ignore C++ style comments (ALSO HANDLED BY CPP) */
199"//"[^\n]*"\n" ;
200
201 /* ignore whitespace */
202{h_white}+ { WHITE_RETURN(' '); }
203({v_tab}|{c_return}|{form_feed})+ { WHITE_RETURN(' '); }
204({h_white}|{v_tab}|{c_return}|{form_feed})*"\n" { NEWLINE_RETURN(); }
205
206 /* keywords */
207_Alignas { KEYWORD_RETURN(ALIGNAS); } // C11
208_Alignof { KEYWORD_RETURN(ALIGNOF); } // C11
209__alignof { KEYWORD_RETURN(ALIGNOF); } // GCC
210__alignof__ { KEYWORD_RETURN(ALIGNOF); } // GCC
211asm { KEYWORD_RETURN(ASM); }
212__asm { KEYWORD_RETURN(ASM); } // GCC
213__asm__ { KEYWORD_RETURN(ASM); } // GCC
214_Atomic { KEYWORD_RETURN(ATOMIC); } // C11
215__attribute { KEYWORD_RETURN(ATTRIBUTE); } // GCC
216__attribute__ { KEYWORD_RETURN(ATTRIBUTE); } // GCC
217auto { KEYWORD_RETURN(AUTO); }
218basetypeof { KEYWORD_RETURN(BASETYPEOF); } // CFA
219_Bool { KEYWORD_RETURN(BOOL); } // C99
220break { KEYWORD_RETURN(BREAK); }
221case { KEYWORD_RETURN(CASE); }
222catch { KEYWORD_RETURN(CATCH); } // CFA
223catchResume { KEYWORD_RETURN(CATCHRESUME); } // CFA
224char { KEYWORD_RETURN(CHAR); }
225choose { KEYWORD_RETURN(CHOOSE); } // CFA
226_Complex { KEYWORD_RETURN(COMPLEX); } // C99
227__complex { KEYWORD_RETURN(COMPLEX); } // GCC
228__complex__ { KEYWORD_RETURN(COMPLEX); } // GCC
229const { KEYWORD_RETURN(CONST); }
230__const { KEYWORD_RETURN(CONST); } // GCC
231__const__ { KEYWORD_RETURN(CONST); } // GCC
232continue { KEYWORD_RETURN(CONTINUE); }
233coroutine { KEYWORD_RETURN(COROUTINE); } // CFA
234default { KEYWORD_RETURN(DEFAULT); }
235disable { KEYWORD_RETURN(DISABLE); } // CFA
236do { KEYWORD_RETURN(DO); }
237double { KEYWORD_RETURN(DOUBLE); }
238dtype { KEYWORD_RETURN(DTYPE); } // CFA
239else { KEYWORD_RETURN(ELSE); }
240enable { KEYWORD_RETURN(ENABLE); } // CFA
241enum { KEYWORD_RETURN(ENUM); }
242__extension__ { KEYWORD_RETURN(EXTENSION); } // GCC
243exception { KEYWORD_RETURN(EXCEPTION); } // CFA
244extern { KEYWORD_RETURN(EXTERN); }
245fallthrough { KEYWORD_RETURN(FALLTHROUGH); } // CFA
246fallthru { KEYWORD_RETURN(FALLTHRU); } // CFA
247finally { KEYWORD_RETURN(FINALLY); } // CFA
248float { KEYWORD_RETURN(FLOAT); }
249__float80 { KEYWORD_RETURN(uuFLOAT80); } // GCC
250float80 { KEYWORD_RETURN(uuFLOAT80); } // GCC
251__float128 { KEYWORD_RETURN(uuFLOAT128); } // GCC
252float128 { KEYWORD_RETURN(uuFLOAT128); } // GCC
253_Float16 { FLOATXX(uFLOAT16); } // GCC
254_Float32 { FLOATXX(uFLOAT32); } // GCC
255_Float32x { FLOATXX(uFLOAT32X); } // GCC
256_Float64 { FLOATXX(uFLOAT64); } // GCC
257_Float64x { FLOATXX(uFLOAT64X); } // GCC
258_Float128 { FLOATXX(uFLOAT128); } // GCC
259_Float128x { FLOATXX(uFLOAT128); } // GCC
260for { KEYWORD_RETURN(FOR); }
261forall { KEYWORD_RETURN(FORALL); } // CFA
262fortran { KEYWORD_RETURN(FORTRAN); }
263ftype { KEYWORD_RETURN(FTYPE); } // CFA
264_Generic { KEYWORD_RETURN(GENERIC); } // C11
265goto { KEYWORD_RETURN(GOTO); }
266if { KEYWORD_RETURN(IF); }
267_Imaginary { KEYWORD_RETURN(IMAGINARY); } // C99
268__imag { KEYWORD_RETURN(IMAGINARY); } // GCC
269__imag__ { KEYWORD_RETURN(IMAGINARY); } // GCC
270inline { KEYWORD_RETURN(INLINE); } // C99
271__inline { KEYWORD_RETURN(INLINE); } // GCC
272__inline__ { KEYWORD_RETURN(INLINE); } // GCC
273int { KEYWORD_RETURN(INT); }
274__int128 { KEYWORD_RETURN(INT128); } // GCC
275int128 { KEYWORD_RETURN(INT128); } // GCC
276__label__ { KEYWORD_RETURN(LABEL); } // GCC
277long { KEYWORD_RETURN(LONG); }
278monitor { KEYWORD_RETURN(MONITOR); } // CFA
279mutex { KEYWORD_RETURN(MUTEX); } // CFA
280_Noreturn { KEYWORD_RETURN(NORETURN); } // C11
281__builtin_offsetof { KEYWORD_RETURN(OFFSETOF); } // GCC
282one_t { NUMERIC_RETURN(ONE_T); } // CFA
283or { QKEYWORD_RETURN(WOR); } // CFA
284otype { KEYWORD_RETURN(OTYPE); } // CFA
285register { KEYWORD_RETURN(REGISTER); }
286restrict { KEYWORD_RETURN(RESTRICT); } // C99
287__restrict { KEYWORD_RETURN(RESTRICT); } // GCC
288__restrict__ { KEYWORD_RETURN(RESTRICT); } // GCC
289return { KEYWORD_RETURN(RETURN); }
290short { KEYWORD_RETURN(SHORT); }
291signed { KEYWORD_RETURN(SIGNED); }
292__signed { KEYWORD_RETURN(SIGNED); } // GCC
293__signed__ { KEYWORD_RETURN(SIGNED); } // GCC
294sizeof { KEYWORD_RETURN(SIZEOF); }
295static { KEYWORD_RETURN(STATIC); }
296_Static_assert { KEYWORD_RETURN(STATICASSERT); } // C11
297struct { KEYWORD_RETURN(STRUCT); }
298switch { KEYWORD_RETURN(SWITCH); }
299thread { KEYWORD_RETURN(THREAD); } // C11
300_Thread_local { KEYWORD_RETURN(THREADLOCAL); } // C11
301throw { KEYWORD_RETURN(THROW); } // CFA
302throwResume { KEYWORD_RETURN(THROWRESUME); } // CFA
303timeout { QKEYWORD_RETURN(TIMEOUT); } // CFA
304trait { KEYWORD_RETURN(TRAIT); } // CFA
305try { KEYWORD_RETURN(TRY); } // CFA
306ttype { KEYWORD_RETURN(TTYPE); } // CFA
307typedef { KEYWORD_RETURN(TYPEDEF); }
308typeof { KEYWORD_RETURN(TYPEOF); } // GCC
309__typeof { KEYWORD_RETURN(TYPEOF); } // GCC
310__typeof__ { KEYWORD_RETURN(TYPEOF); } // GCC
311union { KEYWORD_RETURN(UNION); }
312unsigned { KEYWORD_RETURN(UNSIGNED); }
313__builtin_va_list { KEYWORD_RETURN(VALIST); } // GCC
314virtual { KEYWORD_RETURN(VIRTUAL); } // CFA
315void { KEYWORD_RETURN(VOID); }
316volatile { KEYWORD_RETURN(VOLATILE); }
317__volatile { KEYWORD_RETURN(VOLATILE); } // GCC
318__volatile__ { KEYWORD_RETURN(VOLATILE); } // GCC
319waitfor { KEYWORD_RETURN(WAITFOR); }
320when { KEYWORD_RETURN(WHEN); }
321while { KEYWORD_RETURN(WHILE); }
322with { KEYWORD_RETURN(WITH); } // CFA
323zero_t { NUMERIC_RETURN(ZERO_T); } // CFA
324
325 /* identifier */
326{identifier} { IDENTIFIER_RETURN(); }
327"`"{identifier}"`" { // CFA
328 yytext[yyleng - 1] = '\0'; yytext += 1; // SKULLDUGGERY: remove backquotes (ok to shorten?)
329 IDENTIFIER_RETURN();
330}
331{attr_identifier} { ATTRIBUTE_RETURN(); }
332
333 /* numeric constants */
334{binary_constant} { NUMERIC_RETURN(INTEGERconstant); }
335{octal_constant} { NUMERIC_RETURN(INTEGERconstant); }
336{decimal_constant} { NUMERIC_RETURN(INTEGERconstant); }
337{hex_constant} { NUMERIC_RETURN(INTEGERconstant); }
338{floating_decimal} { NUMERIC_RETURN(FLOATING_DECIMALconstant); } // must appear before floating_constant
339{floating_fraction} { NUMERIC_RETURN(FLOATING_FRACTIONconstant); } // must appear before floating_constant
340{floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
341{hex_floating_constant} { NUMERIC_RETURN(FLOATINGconstant); }
342
343 /* character constant, allows empty value */
344({cwide_prefix}[_]?)?['] { BEGIN QUOTE; rm_underscore(); strtext = new string( yytext, yyleng ); }
345<QUOTE>[^'\\\n]* { strtext->append( yytext, yyleng ); }
346<QUOTE>['\n] { BEGIN 0; strtext->append( yytext, yyleng ); RETURN_STR(CHARACTERconstant); }
347 /* ' stop editor highlighting */
348
349 /* string constant */
350({swide_prefix}[_]?)?["] { BEGIN STRING; rm_underscore(); strtext = new string( yytext, yyleng ); }
351<STRING>[^"\\\n]* { strtext->append( yytext, yyleng ); }
352<STRING>["\n] { BEGIN 0; strtext->append( yytext, yyleng ); RETURN_STR(STRINGliteral); }
353 /* " stop editor highlighting */
354
355 /* common character/string constant */
356<QUOTE,STRING>{escape_seq} { rm_underscore(); strtext->append( yytext, yyleng ); }
357<QUOTE,STRING>"\\"{h_white}*"\n" {} // continuation (ALSO HANDLED BY CPP)
358<QUOTE,STRING>"\\" { strtext->append( yytext, yyleng ); } // unknown escape character
359
360 /* punctuation */
361"@" { ASCIIOP_RETURN(); }
362"`" { ASCIIOP_RETURN(); }
363"[" { ASCIIOP_RETURN(); }
364"]" { ASCIIOP_RETURN(); }
365"(" { ASCIIOP_RETURN(); }
366")" { ASCIIOP_RETURN(); }
367"{" { ASCIIOP_RETURN(); }
368"}" { ASCIIOP_RETURN(); }
369"," { ASCIIOP_RETURN(); } // also operator
370":" { ASCIIOP_RETURN(); }
371";" { ASCIIOP_RETURN(); }
372"." { ASCIIOP_RETURN(); } // also operator
373"..." { NAMEDOP_RETURN(ELLIPSIS); }
374
375 /* alternative C99 brackets, "<:" & "<:<:" handled by preprocessor */
376"<:" { RETURN_VAL('['); }
377":>" { RETURN_VAL(']'); }
378"<%" { RETURN_VAL('{'); }
379"%>" { RETURN_VAL('}'); }
380
381 /* operators */
382"!" { ASCIIOP_RETURN(); }
383"+" { ASCIIOP_RETURN(); }
384"-" { ASCIIOP_RETURN(); }
385"*" { ASCIIOP_RETURN(); }
386"\\" { ASCIIOP_RETURN(); } // CFA, exponentiation
387"/" { ASCIIOP_RETURN(); }
388"%" { ASCIIOP_RETURN(); }
389"^" { ASCIIOP_RETURN(); }
390"~" { ASCIIOP_RETURN(); }
391"&" { ASCIIOP_RETURN(); }
392"|" { ASCIIOP_RETURN(); }
393"<" { ASCIIOP_RETURN(); }
394">" { ASCIIOP_RETURN(); }
395"=" { ASCIIOP_RETURN(); }
396"?" { ASCIIOP_RETURN(); }
397
398"++" { NAMEDOP_RETURN(ICR); }
399"--" { NAMEDOP_RETURN(DECR); }
400"==" { NAMEDOP_RETURN(EQ); }
401"!=" { NAMEDOP_RETURN(NE); }
402"<<" { NAMEDOP_RETURN(LS); }
403">>" { NAMEDOP_RETURN(RS); }
404"<=" { NAMEDOP_RETURN(LE); }
405">=" { NAMEDOP_RETURN(GE); }
406"&&" { NAMEDOP_RETURN(ANDAND); }
407"||" { NAMEDOP_RETURN(OROR); }
408"->" { NAMEDOP_RETURN(ARROW); }
409"+=" { NAMEDOP_RETURN(PLUSassign); }
410"-=" { NAMEDOP_RETURN(MINUSassign); }
411"\\=" { NAMEDOP_RETURN(EXPassign); } // CFA, exponentiation
412"*=" { NAMEDOP_RETURN(MULTassign); }
413"/=" { NAMEDOP_RETURN(DIVassign); }
414"%=" { NAMEDOP_RETURN(MODassign); }
415"&=" { NAMEDOP_RETURN(ANDassign); }
416"|=" { NAMEDOP_RETURN(ORassign); }
417"^=" { NAMEDOP_RETURN(ERassign); }
418"<<=" { NAMEDOP_RETURN(LSassign); }
419">>=" { NAMEDOP_RETURN(RSassign); }
420
421"@=" { NAMEDOP_RETURN(ATassign); } // CFA
422"~=" { NAMEDOP_RETURN(ErangeUpEq); } // CFA
423"-~" { NAMEDOP_RETURN(ErangeDown); } // CFA
424"-~=" { NAMEDOP_RETURN(ErangeDownEq); } // CFA
425
426 /* CFA, operator identifier */
427{op_unary}"?" { IDENTIFIER_RETURN(); } // unary
428"?"({op_unary_pre_post}|"()"|"[?]"|"{}") { IDENTIFIER_RETURN(); }
429"^?{}" { IDENTIFIER_RETURN(); }
430"?`"{identifier} { IDENTIFIER_RETURN(); } // postfix operator
431"?"{op_binary_over}"?" { IDENTIFIER_RETURN(); } // binary
432 /*
433 This rule handles ambiguous cases with operator identifiers, e.g., "int *?*?()", where the string "*?*?" can be
434 lexed as "*?"/"*?" or "*"/"?*?". Since it is common practise to put a unary operator juxtaposed to an identifier,
435 e.g., "*i", users will be annoyed if they cannot do this with respect to operator identifiers. Therefore, there is
436 a lexical look-ahead for the second case, with backtracking to return the leading unary operator and then
437 reparsing the trailing operator identifier. Otherwise a space is needed between the unary operator and operator
438 identifier to disambiguate this common case.
439
440 A similar issue occurs with the dereference, *?(...), and routine-call, ?()(...) identifiers. The ambiguity
441 occurs when the deference operator has no parameters, *?() and *?()(...), requiring arbitrary whitespace
442 look-ahead for the routine-call parameter-list to disambiguate. However, the dereference operator must have a
443 parameter/argument to dereference *?(...). Hence, always interpreting the string *?() as * ?() does not preclude
444 any meaningful program.
445
446 The remaining cases are with the increment/decrement operators and conditional expression:
447
448 i++? ...(...);
449 i?++ ...(...);
450
451 requiring arbitrary whitespace look-ahead for the operator parameter-list, even though that interpretation is an
452 incorrect expression (juxtaposed identifiers). Therefore, it is necessary to disambiguate these cases with a
453 space:
454
455 i++ ? i : 0;
456 i? ++i : 0;
457 */
458{op_unary}"?"({op_unary_pre_post}|"()"|"[?]"|{op_binary_over}"?") {
459 // 1 or 2 character unary operator ?
460 int i = yytext[1] == '?' ? 1 : 2;
461 yyless( i ); // put back characters up to first '?'
462 if ( i > 1 ) {
463 NAMEDOP_RETURN( yytext[0] == '+' ? ICR : DECR );
464 } else {
465 ASCIIOP_RETURN();
466 } // if
467}
468
469 /* unknown character */
470. { yyerror( "unknown character" ); }
471
472%%
473
474// ----end of lexer----
475
476void yyerror( const char * errmsg ) {
477 SemanticErrorThrow = true;
478 cerr << (yyfilename ? yyfilename : "*unknown file*") << ':' << yylineno << ':' << column - yyleng + 1
479 << ": " << ErrorHelpers::error_str() << errmsg << " at token \"" << (yytext[0] == '\0' ? "EOF" : yytext) << '"' << endl;
480}
481
482// Local Variables: //
483// mode: c++ //
484// tab-width: 4 //
485// compile-command: "make install" //
486// End: //
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